X-Git-Url: https://sigrok.org/gitweb/?p=libsigrokdecode.git;a=blobdiff_plain;f=decoders%2Fonewire_network%2F__init__.py;h=25b3f5d4cce3d7b32bb793830b36efee0b140931;hp=0a712ef2bbce3b3ebd946d826394de6b763a46cf;hb=6188e4e41ef0d9468a1b9f9bad5637ca862d73df;hpb=9cfb16e8532e34b40edf1d980c7438afb31668e0 diff --git a/decoders/onewire_network/__init__.py b/decoders/onewire_network/__init__.py index 0a712ef..25b3f5d 100644 --- a/decoders/onewire_network/__init__.py +++ b/decoders/onewire_network/__init__.py @@ -19,60 +19,44 @@ ## ''' -1-Wire protocol decoder. +1-Wire protocol decoder (network layer). -The 1-Wire protocol enables bidirectional communication over a single wire (and -ground) between a single master and one or multiple slaves. The protocol is -layered, the provided parser decodes the next layers: -- Link layer (reset, presence detection, reading/writing bits) -- Network layer (skip, search, match device ROM addresses) -The higher layers (transport, presentation) are not decoded, since they are -mostly device specific and it would take a lot of code to interpret them. +The 1-Wire protocol enables bidirectional communication over a single wire +(and ground) between a single master and one or multiple slaves. The protocol +is layered: -Sample rate: -A high enough sample rate is required to properly detect all the elements of -the protocol. A lower sample rate can be used if the master does not use -overdrive communication speed. The next minimal values should be used: -- overdrive available: 2MHz minimum, 5MHz suggested -- overdrive not available: 400kHz minimum, 1MHz suggested + - Link layer (reset, presence detection, reading/writing bits) + - Network layer (skip/search/match device ROM addresses) + - Transport layer (transport data between 1-Wire master and device) -Probes: -1-Wire requires a single signal, but some master implementations might have a -separate signal use to deliver power to the bus during temperature conversion -as an example. This power signal is currently not parsed. -- owr (1-Wire bus) -- pwr (1-Wire power) +Network layer: -Options: -1-Wire is an asynchronous protocol, so the decoder must know the sample rate. -The timing for sampling bits, presence and reset is calculated by the decoder, -but in case the user wishes to use different values, it is possible to -configure the next timing values (number of sample rate periods): -- overdrive (if active the decoder will be prepared for overdrive) -- cnt_normal_bit (time for normal mode sample bit) -- cnt_normal_presence (time for normal mode sample presence) -- cnt_normal_reset (time for normal mode reset) -- cnt_overdrive_bit (time for overdrive mode sample bit) -- cnt_overdrive_presence (time for overdrive mode sample presence) -- cnt_overdrive_reset (time for overdrive mode reset) -This options should be configured only on very rare cases and the user should -read the decoder source code to understand them correctly. +Protocol output format: +TODO. Annotations: -Annotations can be shown for each layer of the protocol separately: -- link (the value of each transmitted bit is shown separately) -- network (the ROM command, and address are shown) -- transport (only transport layer byte transfers are shown) -If link layer annotations are shown, possible issues with sample rate and sample -timing are also shown. + +The following link layer annotations are shown: + + - RESET/PRESENCE True/False + The event is marked from the signal negative edge to the end of the reset + high period. It is also reported if there are any devices attached to the + bus. + +The following network layer annotations are shown: + + - ROM command + The requested ROM command is displayed as an 8bit hex value and by name. + - ROM + The 64bit value of the addressed device is displayed: + Family code (1 byte) + serial number (6 bytes) + CRC (1 byte) + - Data + Data intended for the transport layer is displayed as an 8bit hex value. TODO: -- add CRC checks for network layer -- add transport layer code -- review link layer code, to check for protocol correctness -- define output protocol + - Add CRC checks, to see if there were communication errors on the wire. + - Add reporting original/complement address values from the search algorithm. ''' -from .onewire_link import * from .onewire_network import *